The technology of the present disclosure relates to an optical scanning device that scans a peripheral surface of an image carrying member with light beams and an image forming apparatus including the same.
An image forming apparatus such as a laser printer and a copy machine includes an optical scanning device that performs scanning exposure of a peripheral surface of a photosensitive drum (an image carrying member) with light beams and forms an electrostatic latent image on the peripheral surface. For example, as an example of the optical scanning device, there has been known a multi-beam type optical scanning device. The multi-beam type optical scanning device includes a light source in which there are a plurality of light emitting parts (laser diodes) that emit light beams.
In the multi-beam type optical scanning device, each light emitting part of the light source normally has a main scanning pitch and a sub-scanning pitch and is arranged along a predetermined arrangement direction. Furthermore, in order to form an electrostatic latent image according to image data on a peripheral surface of a photosensitive drum, a light emitting start timing of each light emitting part is set in accordance with the main scanning pitch. A light beam is emitted from each light emitting part at a predetermined light emitting start timing. The emitted each light beam draws a main scanning line along a main scanning direction on the peripheral surface of the photosensitive drum in a state of keeping an interval in a sub-scanning direction in accordance with the sub-scanning pitch. In this way, the optical scanning device can form the electrostatic latent image according to the image data on the peripheral surface of the photosensitive drum.